Y(4626) as a molecular state from interaction $${D}^*_s{\bar{D}}_{s1}(2536)-{D}_s{\bar{D}}_{s1}(2536)$$

Abstract

AbstractRecently, a new structure Y(4626) was reported by the Belle Collaboration in the process $$e^+e^-\rightarrow D_s^+D_{s1}(2536)^-$$e+e-→Ds+Ds1(2536)-. In this work, we propose an assignment of the Y(4626) as a $${D}^*_s{\bar{D}}_{s1}(2536)$$Ds∗D¯s1(2536) molecular state, which decays into the $$D_s^+D_{s1}(2536)^-$$Ds+Ds1(2536)- channel through a coupling between $${D}^*_s{\bar{D}}_{s1}(2536)$$Ds∗D¯s1(2536) and $${D}_s{\bar{D}}_{s1}(2536)$$DsD¯s1(2536) channels. With the help of the heavy quark symmetry, the potential of the interaction $${D}^*_s{\bar{D}}_{s1}(2536)-{D}_s{\bar{D}}_{s1}(2536)$$Ds∗D¯s1(2536)-DsD¯s1(2536) is constructed within the one-boson-exchange model, and inserted into the quasipotential Bethe–Salpeter equation. The pole of obtained scattering amplitude is searched for in the complex-energy plane, which corresponds to a molecular state from the interaction $${D}^*_s{\bar{D}}_{s1}(2536)-{D}_s{\bar{D}}_{s1}(2536)$$Ds∗D¯s1(2536)-DsD¯s1(2536). The results suggest that a pole is produced near the $${D}^*_s{\bar{D}}_{s1}(2536)$$Ds∗D¯s1(2536) threshold, which exhibits as a peak in the invariant mass spectrum of the $${D}_s{\bar{D}}_{s1}(2536)$$DsD¯s1(2536) channel at about 4626 MeV. It obviously favors the Y(4626) as a $${D}^*_s{\bar{D}}_{s1}(2536)$$Ds∗D¯s1(2536) molecular state. In the same model, other molecular states from the interaction $${D}^*_s{\bar{D}}_{s1}(2536)-{D}_s{\bar{D}}_{s1}(2536)$$Ds∗D¯s1(2536)-DsD¯s1(2536) are also predicted, which can be checked in future experiments.